The best approach to ensure compliance with a policy requiring all data at rest be encrypted while maintaining performance is to deploy full disk encryption (FDE) on all endpoints and servers. FDE encrypts the entire storage volume—including the operating system, applications, and all data at rest—at the block level, typically using AES-256, with minimal performance overhead because encryption and decryption are handled by the disk controller or CPU via hardware acceleration like AES-NI. On the ISC2 Certified in Cybersecurity CC exam, this question tests your understanding of balancing security requirements with operational impact; a common trap is choosing file-level encryption, which can degrade performance and miss system files. Remember that FDE covers everything on the drive without slowing down daily tasks, making it the most efficient compliance solution. Memory tip: “FDE = Full Drive Encryption, Full Speed.”
ISC2 CC Security Principles Practice Question
This CC practice question tests your understanding of security principles. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A company's security policy requires that all data at rest be encrypted. Which of the following is the BEST approach to ensure compliance while maintaining performance?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "best"
Why it matters: Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
Deploy full disk encryption on all endpoints and servers.
Full disk encryption encrypts the entire drive, ensuring all data at rest is protected with minimal performance overhead when using hardware-based encryption.
B
Use database encryption to protect sensitive data.
Why wrong: Database encryption only protects data within the database, not other data at rest such as logs or backups.
C
Apply network encryption using TLS for all data transfers.
Why wrong: Network encryption protects data in transit, not at rest.
D
Implement file-level encryption for sensitive files only.
Why wrong: File-level encryption can be complex and may not cover all data, potentially leaving some data unencrypted.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Deploy full disk encryption on all endpoints and servers.
Full disk encryption (FDE) encrypts the entire storage volume, including the operating system, applications, and all data at rest, ensuring compliance with a policy requiring all data at rest to be encrypted. FDE operates at the block level, typically using AES-256, with minimal performance overhead because encryption and decryption are handled by the disk controller or CPU with hardware acceleration (e.g., AES-NI), making it the best approach for maintaining performance while meeting the broad requirement.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✓
Deploy full disk encryption on all endpoints and servers.
Why this is correct
Full disk encryption encrypts the entire drive, ensuring all data at rest is protected with minimal performance overhead when using hardware-based encryption.
Clue confirmation
The clue word "best" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
Use database encryption to protect sensitive data.
Why it's wrong here
Database encryption only protects data within the database, not other data at rest such as logs or backups.
✗
Apply network encryption using TLS for all data transfers.
Why it's wrong here
Network encryption protects data in transit, not at rest.
✗
Implement file-level encryption for sensitive files only.
Why it's wrong here
File-level encryption can be complex and may not cover all data, potentially leaving some data unencrypted.
Common exam traps
Common exam trap: answer the scenario, not the keyword
ISC2 often tests the distinction between 'data at rest' and 'data in transit' encryption, and the trap here is that candidates may choose database or file-level encryption because they think it is more targeted, but they overlook the policy's explicit 'all data at rest' requirement, which only full disk encryption satisfies comprehensively.
Detailed technical explanation
How to think about this question
Full disk encryption (FDE) typically uses a symmetric encryption algorithm like AES-256 in XTS mode (e.g., BitLocker, FileVault, LUKS) and encrypts each sector independently, allowing random access without decrypting the entire disk. The encryption key is derived from a user passphrase or hardware TPM, and the performance impact is often less than 5% on modern systems with AES-NI instructions, whereas file-level encryption (e.g., EFS) requires per-file key management and can cause fragmentation or latency when accessing many small files.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A developer is choosing between AES-256 (symmetric) and RSA-2048 (asymmetric) for encrypting a large file that will be sent to a partner. Symmetric encryption is fast but requires key exchange; asymmetric is slower but solves the key distribution problem. A hybrid approach — encrypt the file with AES, encrypt the AES key with RSA — is standard. Questions like this test whether you understand when each approach applies.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this CC question in full detail.
Security Principles — This question tests Security Principles — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Deploy full disk encryption on all endpoints and servers. — Full disk encryption (FDE) encrypts the entire storage volume, including the operating system, applications, and all data at rest, ensuring compliance with a policy requiring all data at rest to be encrypted. FDE operates at the block level, typically using AES-256, with minimal performance overhead because encryption and decryption are handled by the disk controller or CPU with hardware acceleration (e.g., AES-NI), making it the best approach for maintaining performance while meeting the broad requirement.
What should I do if I get this CC question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "best". Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
This CC practice question is part of Courseiva's free ISC2 certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the CC exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.